I have a commit note as well, but starting with "30615c6eaaaf310034e8" an attribute alias setup through the :alias_attribute method is either removed or never set. I added some failing specs showing this against HEAD, but was also able to lock my project against the previous commit "31f5fd3a7ef363af9d8d" and verified that :alias_attribute was working at that point.

Here is the url to the failing specs:

https://github.com/davekrupinski/mongoid/commit/20961f2db0e70e06d0b99a1fa881f96cb9d125f9

Thanks,
dave